Fix for #39

[dimbleby]

Avoid definitions in inner modules being dependent on things that may
only be in scope in outer modules.

[dimbleby]

I'm not particularly attached to this if it doesn't work for some cases; but it does the job for me.

[nox]

Interesting fix! Will try in cocoa-rs.

[nox]

@dimbleby That fixes the values, but not the type of the enum. This additional patch fixes the types:

diff --git i/src/lib.rs w/src/lib.rs
index d687d3f..5782cc7 100644
--- i/src/lib.rs
+++ w/src/lib.rs
@@ -231,11 +231,13 @@ macro_rules! bitflags {
                     // private, which prevents us from using it to define
                     // public constants.
                     pub struct $BitFlags {
-                        bits: $T,
+                        bits: usize,
                     }
                     mod real_flags {
                         use super::$BitFlags;
-                        $($(#[$Flag_attr])* pub const $Flag: $BitFlags = $BitFlags { bits: super::super::$Flag.bits };)+
+                        $($(#[$Flag_attr])* pub const $Flag: $BitFlags = $BitFlags {
+                            bits: super::super::$Flag.bits as usize
+                        };)+
                     }
                     // Now we define the "undefined" versions of the flags.
                     // This way, all the names exist, even if some are #[cfg]ed
@@ -243,7 +245,7 @@ macro_rules! bitflags {
                     $(const $Flag: $BitFlags = $BitFlags { bits: 0 };)+

                     #[inline]
-                    pub fn fmt(self_: $T,
+                    pub fn fmt(self_: usize,
                                f: &mut $crate::__core::fmt::Formatter)
                                -> $crate::__core::fmt::Result {
                         // Now we import the real values for the flags.
@@ -253,7 +255,7 @@ macro_rules! bitflags {
                         let mut first = true;
                         $(
                             // $Flag.bits == 0 means that $Flag doesn't exist
-                            if $Flag.bits != 0 && self_ & $Flag.bits == $Flag.bits {
+                            if $Flag.bits != 0 && self_ & $Flag.bits as usize == $Flag.bits as usize {
                                 if !first {
                                     try!(f.write_str(" | "));
                                 }
@@ -264,7 +266,7 @@ macro_rules! bitflags {
                         Ok(())
                     }
                 }
-                dummy::fmt(self.bits, f)
+                dummy::fmt(self.bits as usize, f)
             }
         }

@@ -283,21 +285,23 @@ macro_rules! bitflags {
                 #[allow(dead_code)]
                 mod dummy {
                     pub struct $BitFlags {
-                        bits: $T,
+                        bits: usize,
                     }
                     mod real_flags {
                         use super::$BitFlags;
-                        $($(#[$Flag_attr])* pub const $Flag: $BitFlags = $BitFlags { bits: super::super::$Flag.bits };)+
+                        $($(#[$Flag_attr])* pub const $Flag: $BitFlags = $BitFlags {
+                            bits: super::super::$Flag.bits as usize
+                        };)+
                     }
                     $(const $Flag: $BitFlags = $BitFlags { bits: 0 };)+

                     #[inline]
-                    pub fn all() -> $T {
+                    pub fn all() -> usize {
                         use self::real_flags::*;
                         $($Flag.bits)|+
                     }
                 }
-                $BitFlags { bits: dummy::all() }
+                $BitFlags { bits: dummy::all() as $T }
             }

             /// Returns the raw value of the flags currently stored.

Feel free to amend your PR with this if you want.

[dimbleby]

@nox - thanks! will do

[Amanieu]

Wouldn't it be better to use u64 instead of usize? The optimizer should be able to reduce it down to the proper size anyways.

[nox]

@Amanieu True that! It should be u64 given you can do u64 bitflags on a 32 bits system. Nice catch.

[alexreg]

This is a useful PR. @alexcrichton Any chance of a merge and possible release? :)

[alexcrichton]

Thanks @dimbleby!